Horizontal scanning rate correction apparatus for beam index color cathode-ray tube
US4281340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1979 |
| Grant date | Jul 28, 1981 |
| Priority date | — |
| Expiry date | Dec 3, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Horizontal scanning rate correction apparatus is provided for beam index color cathode-ray tubes of the type having a screen, an electron gun for projecting an electron beam upon the screen, a plurality of index elements positioned to be struck by the electron beam as it scans across the screen, a deflection device for causing the electron beam to repeatedly scan across the screen in a vertical succession of horizontal lines, and an index signal processing circuit for producing an index signal having a frequency determined by the frequency of the incidence of the electron beam upon the index elements as it scans horizontal lines and for controlling color switching circuitry which determines which of a plurality of color signals modulates the intensity of the electron beam. The horizontal scanning rate correction apparatus includes a memory circuit for storing correction values derived from the index signal processing circuit during horizontal scanning by the electron beam and representing the deviation of the horizontal scanning rate from a desired scanning rate at each of a plurality of horizontal sampling positions along a horizontal line. The apparatus further includes circuitry…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.